Mortar training device and components thereof



MORTAR TRAINING DEVICE AND COMPONENTS THEN-EOF Filed May 19, 1953 Feb. 4, 1958 w. D. ALDERSON 2 Sheets-Sheet l 4 w. D. ALDERsoN MORTAR TRAINING DEVICE AND COMPONENTS THEREOF Feb. 4, 1958 2 Sheets-Sheet 2 Filed May 19. 1953 w WQ, my m 000 United States Patent O fi MORTAR TRAINING DEVICE AND COMPONENTS THEREOF William D. Alderson, Chicago, Ill., assignor to Patent {cen'se Corporation, Chicago, Ill., a corporation of mois Application May 19, 1953, Serial No. 355,967

4 Claims. (Cl. 102-49) The present invention relates to improvements in a device for training military personnel in the aiming, the tiring, and the observation and maintenance of the mortar as a military weapon. It is particularly concerned with improvements in a device of the same general type which is the subject matter of my earlier filed application, Serial No. 231,823, filed June 15, i951, now U. S. Patent 2,786,415. These improvements concern structural features of a training or dummy projectile of approximately the same size, weight and shape as a standard mortar round of a given caliber, a standard round being employed as the hollow body portion of the dummy, including novel provisions for the automatic ejection of the same yfrom the bore of a mortar tube upon ring of a miniature or sub-caliber projectile from a bore of the dummy projectile; as well as novel provisions enabling the trajectory of the sub-caliber projectile fired to be quickly and accurately adjusted. Novel provisions are also made to facilitate and expedite re-loading of the dummy projectile when it has fired the sub-caliber round and been ejected from the tube; and these provisions include means for re-loading the dummy for automatic self-ejection and with a propellent charge or cartridge for the sub-caliber projectile.

It is thus seen that it is one object of the invention to provide a mortar training device employing a dummy projectile which is very cheaply produced since its main body portion thereof is afforded by a standard, government issued mortar round which can be quite inexpensively equipped with an internal coaxial sub-caliber tube. Associated with this tube s a novel adjustable bleeder valve, preferably of the needle type, by which the range of a sub-caliber projectile, propelled by a given caliber blank cartridge as a tiring charge, can be selected and set as desired by control of its velocity, this through a predetermined adjustable by-passing of the propellent gases out of the sub-caliber bore.

A still further object of the invention is to provide velocity control-range selector means for a dummy projectile as described in the preceding paragraph, in which a manually adjustable bleeder valve for by-passing a desired fraction of the propellent blast from the sub-caliber bore is conveniently accessible from the exterior of the body, the valve controlling a bleeder vent or port through the sub-caliber bore to the interior of the mortar rounds body, and the body in turn having an exhaust passage through its wall which opens to the exterior of the round at a point forward of the usual bourrlet. Thus burning gas released by bleeder action has no elect in the space in the mortar tube rearwardly of the bourrlet in which the dummy projectile ejector charge subsequently acts to expel the dummy automatically 'from the mortar tube.

The invention also provides an improved iinned tail and ejector assembly on the dummy round in which a slidable striker tube is adapted for impact engagement with the base of the mortar tube; this tube mounts a delayed action ejector cartridge which is projected into tiring engagenient with a tiring pin unit, which in turn tires the pro- '2,821,923 Patented Feb. 4, 1958 pellent cartridge for a sub-caliber round in the dummy projectile bore. The iiring pin unit thus simultaneously ICC detonates the last named propellent charge and initiates detonation of the delayed action ejector charge, byl which the dummy projectile is propelled out of the mortar bore with moderate force after the sub-caliber round has left the dummys sub-caliber tube and the mortar tube. This safely eliminates a waste of time required to recover the dummy projectile after each practice iii-ing round.

Still more specifically, the invention provides an improved dummy projectile for mortar training practice, of the sort described in the preceding paragraph, wherein a (forward body and sub-caliber bore portion has an improved finned tail and ejector assembly hingedly connected thereto, as well as a novel. tiring pin assembly, similarly hinged to the body on a common axis. The tiring pin assembly may thus be quickly pivoted out of operative relation to both the body and tail assembly so as to facilitate the loading and reloading `of the former with a blank sub-caliber propellent cartridge and the loading and reloading ofthe latter with a new delayed action dummy projectile ejecting cartridge. The body firing pin assembly and tail assembly are held in operative relationship to one another by means of a quickly releasable latch device.

Yet another specific object of the invention is to provide a dummy projectile as described above, in which a slidable tiring tube in the tail assembly is forced against a liring pin unit or assembly disposed forwardly thereof upon gravity impact with the bottom of the mortar tube, thus detonating a delayed action charge held in the tube, and causing the tiring pin assembly to detonate at the same instant a propellent charge in the sub-caliber tube forwardly of the tiring pin assembly.

ln another phase, it is an object of the -invention to provide an improved miniature or sub-caliber mortar projectile, preferably for use with a dummy projectile of the foregoing type, which embodies improved provisions to prevent premature firing of a blank cartridge employed therein as a spotting charge, in the form of means to prevent inertia impact of a slidable firing pin thereof with the spotting charge under the force of the impact of the dummy projectile, in which the round is mounted, with the bottom of the mortar tube. Insurance is thus had that the spotting charge of the sub-caliber round will be detonated solely by impact at its point of destination.

Generally considered, it is an object of the invention to provide an improved weapon training device having as its components a dummy round, a sub-caliber round which is tired therefrom, and a delayed action ejector charge which automatically expels the dummy from a weapon tube in which it is used, preferably under moderate force, at the time the sub-caliber round is tired, or shortly thereafter.

The foregoing statements are indicative in a general way of the nature of the invention. Other and more specific objects will be apparent to those skilled in the art upon a full understanding of the construction and operation of the device.

A single embodiment of the invention is presented herein for purpose of illustration. However, it will be appreciated that the invention may be incorporated in other modified forms coming equally within the scope of the appended claims.

ln the drawings:

Fig. 1 is a view in side elevation illustrating the dummy or training projectile of the device;

Fig. 2 is a view in longitudinal or axial section through the projectile of Fig. l, showing the same at the instant of its gravity impact engagement with the bottom of a standard mortar tube;

Figs. 3 and 4 are, respectively, views in horizontal SCC- tion through the projectile of Figs. 1 and 2 along lines 3-3 and 4 4, respectively, further illustrating detailsl of its latched tiring pin assembly and valved velocity control range setting device; and

Fig. 5 is a view in longitudinal or axial section, and in considerably enlarged scale, through an improved subcaliber projectile which is well suited for use in the dummy projectile of Figs. l-4.

The improved mortar training device is made up, in addition to a standard artillery mortar tube T of appropriate bore or caliber, of three main components. These are a dummy mortar round or projectile, illustrated in Figs. 1 and 2 and generally designated 10, a miniature sub-caliber round or projectile 11 (Figs. 2 and 5), and an improved delayed action ejecting charge for the dummy projectile, generally designated 12 and shown only in Fig. 2.

Dummy projectile includes a hollow main body 13 which is supplied by the body of a standard mortar round of desired caliber; a tiring pin assembly, generally designated 14, and a nned tail assembly 15, with an associated delayed action ejector firing unit 16, are mounted in operative hinged, releasably latched relation to the body 13. Body 13 also features an improved velocity control unit, generally designated 17, by which the yardage of the trajectory of sub-caliber projectile 11 may be regulated as desired to simulate combat conditions.

As illustrated in Fig. 2 of the drawings, the body 13 is provided withan open forward end 18, through which a sub-caliber tube 19 projects, this tube being held in place by a conical nose 20 of a suitable plastic composition. Nose 20 is shown threadedly engaged in the forward end 18 of the body.

The reference numeral 21 designates the usual annular bourrelet of the mortar round and it will be noted that the wall of body 13 is provided with one or more generally radial vent passages 22 opening to its exterior in a zone forward of the bourrelet, for a purpose to be described.

Tube 19 has an axial adapter tube or extension 23 rigidly secured in its rear opening, and adapter tube 23 is in turn rigidly secured in a rear axial opening 24 in body 13. A propellent charge for miniature round 11, such as a .22 caliber blank cartridge 25, is shown fitted in the bore adapter 23, with the cartridge rim abutting the rear of the adapter.

Dummy projectile body 13 is also modified by radially drilling the wall thereof adjacent its rear, as indicated at 26, for the reception of a bushing 27 of circular cross section, the bushing being fitted in aperture 26 and united to the body by welding about the joint. Bushing 27 has a tapped bore 28 which threadedly receives an adjustable needle valve 29, which is thus engageable and disengageable with reference to an aligned radial bleeder orifice 30 in sub-caliber adapter extension 23. A knurled nger piece 31 is secured on needle valve 29, and a small, spring urged click detent 32 is adapted to engage in circumferentially spaced recesses in the inner surface of the linger piece. This enables a desired setting of the needle valve, providing a desired bleeder opening of orifice 30 or a complete closure thereof, to be readily and quickly made.

The releasably latched firing pin assembly 14 is supported on a rear annular extension 33 of body which is welded in encircling relation to a reduced rear portion 34 of the tube adapter extension 23. Body extension 33 is provided with a pair of spaced, downwardly de pending pivot ears 35 at one side thereof, and the other side thereof is provided with a vertically disposed, laterally opening slot 36, in which a depending retainer latch 37 is pivoted on a transversely extending hinge pin 38. Latch 37 carries an upwardly extending manipulating por tion, against which a small coil spring 39 bears to urge the latch in clockwise direction about hinge pin 38.

A. transverse hinge pin 40 on pivot ears 35 of body extension 33 serves as a pivot for finned tail assembly 1S, for a block or bolt 41 of firing pin assembly 14, and for a ring pin 42 of the latter. Details of these units are shown in Fig. 3 of the drawings.

Referring to that gure, in conjunction with Fig. 2, hinge pin 40 is shown as being pivotally engaged, immediately inwardly of the depending body pivot ears 35, by the pivot ears 43 of a depending tail and ejector assembly mounting block 44. A pair of screws 45 (Fig. 2) lixedly secure to block 44 a tubular body portion 46 of tail assembly 15, to which radially projecting, circumferentially spaced tins 47 are appropriately secured. Tail body 46 is coaxial with sub-caliber tube or bore 19.

A oating ejector chamber, in the form of an elongated cylindrical tube 48, is slidably received in the interior of tubular body 46, being sustained therein by means of a stop ring 49 threaded in the lower end of the tail body. This ring is engaged by a small annular shoulder on chamber 48 to limit downward movement of the latter. The chamber is radially apertured at 50, adjacent its rear extremity, for the egress of burned gases from delayed action ejecting charge or cartridge 12, which is substained therein. An enlarged head 52 of this cartridge radially overlaps and is supported by the upper extremity of chamber 48.

The bolt 41 of tiring pin assembly 14 is pivoted on hinge pin 40 immediately inwardly of tail assembly hinging ears 43. This is done by a pair of integral laterally projecting pivot ears 53 on the bolt. The latter is provided with a Vertical opening 54 therethrough, olset slightly from the center of the bolt, which receives the upwardly extending striker 55 of firing pin 42. Firing pin 42 is pivoted on hinge pin 40 by an integral pivot ear 56 received between bolt hinge ears 53, and has a center lire striker on its lower surface. This striker is engageable with delayed action cartridge 12 to detonate the same when chamber 48 impact-engages the bottom of mortar tube T. The upper striker 55 has a similar function in relation to the miniature round propellent, i. e., blank cartridge 25.

` Spring urged latch 37 holds tail assembly 15 and firing pin assembly 14 in operative position in the manner shown in Fig. 2. A radially inwardly directed nose 57 on the latch is engageable beneath a shoulder 58 on the adjacent portion of tubular tail assembly body 46 to hold the latter, the bolt 41 and the ring pin 42 in proper position. When the linger piece of latch 37 is depressed against the force of its spring, these parts swing downwardly and outwardly, and may be separated from one another, as illustrated in dotted lines in Fig. 1, to facilitate removal and reloading of a spent propellent charge 25 and dummy ejector charge 12.

Ejector charge 12 may be in the form of a special .38 caliber blank cartridge provided with a delay powder charge. This powder charge is ignited by a primer upon detonation of the latter by the center lire striker of firing pin 42. The relatively slow burning delay powder ignites a booster charge, which in turn ignites a black powder charge sealed therebeneath in the shell of cartridge 12. Delayed action cartridges of this general type are known to the art, and can be readily adapted to the requirements of the present device. Cartridge 12 will lob dummy round 10 a short distance out of the mouth of tube T an instant after miniature projectile 11 is fired out of the mouth of the tube. The dummy can be quickly recovered, reloaded and reset for range, if desired, by the velocity control described above.

Details of sub-caliber projectile 11 are illustrated in Fig. 5 of the drawings. It includes a nose 60 provided with an internal cylindrical chamber 61 for the reception of a spotting charge 62, which may be constituted by a .22 caliber cartridge, the rim of this cartridge bearing upwardly against the lower surface of a reduced, externally threaded rear extension 63 of nose 60.

A. Central tubular body portion 64 is threaded on extension 63, being cylindrically chambered at 65 for the sliding reception of a tiring pin 66. The rear portion of the firing pin 66 is enlarged at 67 to furnish an annular forward shoulder against which a coil compression spring 68 engages. This spring urges the firing pin to the rear, into engagement or abutment with a tail assembly 69 which is threaded in the rear of chambered body 64. Assembly 69 is provided with characteristic fins 70, so that sub-caliber projectile 11 generally simulates, in miniature the appearance of a standard mortar round. Nose 60 of projectile 11 is drilled to provide one or more outwardly and rearwardly directed vents 71 from spotting charge chamber 61 to its exterior.

When the sub-caliber projectile 11 is dropped linto tube 'I and is projected from the sub-caliber tube 19 by detonation of propellent charge 25, its coil spring 68 urges the ring pin 66 rearwardly and prevents it from striking and detonating spotting charge 62 by inertia at the instant of impact with the bottom of the tube. However, when projectile nose 60 strikes the target surface, the inertia is much greater and firing pin 66 is projected violently forward, overcoming spring 68 and detonating cartridge 62. Thereupon a visible spotting charge issues from the vents 71 to indicate the result of the firing.

In loading dummy projectile for use its latch 37 is released 4and tail and tiring pin assemblies 14, 15 are swung downwardly and outwardly away from the rear adapter 33 of the mortar round body. Tail assembly 15 is also swung outwardly about hinge pin 40 so that both the adapter extension bore 24 of the sub-caliber tube and the forward extremity of oating chamber 48 are exposed and accessible for the loading of the respective cartridges 25 and 12. When these operations are performed, the assemblies are swung back into the operative position and latched as illustrated in Fig. 2.

An appropriate setting of the velocity control unit 17 is now made, in accordance with the desired range or e1evation of trajectory of sub-caliber projectile 11. This is done by rotatively manipulating the linger piece 31, thereby adjustably positioning needle valve 29 with reference to the orifice 30. The needle valve is predeterminedly positioned in calibrated settings by spring detent 32.

With dummy projectile 10 so prepared for firing, it is dropped into the mortar tube. Impact of oating chamber 48 with the bottom of the latter causes the chamber to be projected upwardly and ejecting charge 12 to violently engage the ring pin 42. Ignition of cartridge 12 s initiated and it projects the striker 55 of the ring pin into firing engagement with the sub-caliber charge 25. The latter is detonated and the burning gases therefrom expel dummyprojectile 11 out of sub-caliber tube 19. A certain portion of the burning gases is bled through orice 30 to the interior of dummy projectile body 30, depending upon the degree of closure of orifice 30 by needle valve 39, whence this by-passed gas exits through the body vent 22 to the exterior of the body, having no effect on the ensuing ejection of dummy 10 by cartridge 12, as described above.

I claim:

l. A weapon training device comprising a sub-caliber tube, tiring pin and ejector units mounted in hinged relation to said tube to swing into and out of operative coaxial relation to the same and to one another, and means releasably holding said tube and units in said coaxial relation, said ejector unit having means to removably support an ejector charge rearwardly of said tiring pin unit and said sub-caliber tube removably receiving a subcaliber propellent charge forwardly of said ring pin unit.

2. A weapon training device comprising a sub-caliber tube, firing pin and ejector units mounted in hinged relation to said tube to swing into and out of operative coaxial relation to the same and to one another, and means releasably holding said tube and units in said coaxial relation, said ejector unit having means to removably support an ejector charge rearwardly of said firing pin unit and said sub-caliber tube removably receiving a sub-caliber propellent charge forwardly of said firing pin unit, said means including an axial floating chamber in said ejector unit in which said ejector charge is carried into firing engagement with said firing pin unit.

3. A weapon training device comprising a hollow body simulating a Weapon round and having a sub-caliber tube mounted coaxially therein, firing pin and ejector units mounted in hinged relation to said body to swing into and out of operative coaxial relation to the same and to one another, and means releasably holding said body and units in said coaxial relation, said ejector unit having means to removably support an ejector charge rearwardly of said tiring pin unit and said sub-caliber tube removably receiving a` sub-caliber propellent charge forwardly of said tiring pin unit.

4. A weapon training device comprising a hollow body simulating a weapon round and having a sub-caliber tube mounted coaxially therein, tiring pin and ejector units mounted in hinged relation to said body to swing into and out of operative coaxial relation to the same and to one another, and means releasably holding said body and units in said coaxial relation, said ejector unit having means to removably support an ejector charge rearwardly of said firing pin unit and said snb-caliber tube removably receiving a sub-caliber propellent charge forwardly of said tiring pin unit, said means including an axially oating chamber in said ejector unit in which said ejector charge is carried into firing engagement with said firing pin unit.

References Cited in the le of this patent U. s. DEPARTMENT 0F COMMERCE PATENT OFFICE CERTIMCATE oF CoRCTIoN Patent Ne, 2,821,923 February w 195e William Do Alderson It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.,

Column 3, line 45, after "bore" insert of ce; column o, line 20, for "axial" read e@ axially Signed and sealed this 15th day of April 1.958.,

(SEAL) Attest:

KARL H., XLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents `-n E U. S. DEPARTMENT OF COMMERCE PATENT OFFICE I CERTIFICATE OF CORRECTION Pv'zcan't 2,821,923 February 4p 1958 William Do AAlderson Column 3 line 4b,q after "boref insert of m; column 6y line 20, for "axial" read axially Signed and sealed this 15th day of April l958 (SEAL) u At'est:

KARL H., AXLINE ROBERT c. wATsoN Attesting Officer Comissioner of Patents U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION paient 298212923 February 4, 1958 William 1Do Alderson Column 3, line 45, aft-er "bore" :Insert of m; column 6, line 20, for "axial" read axially Signed and sealed this 15th day of April 1.958,.

(SEAL) Atest:

KARL H AXLINE ROBERT c. wATsoN Attesting Officer Comnssioner of Patents 

